A third of health workers in the New York City public hospital system declined COVID-19 vaccines, Mayor Bill de Blasio said Tuesday, as he tried to explain the city-run hospitals' lagging vaccination numbers.

"It's a real issue and we've got to look it in the eye," de Blasio said. "It's understandable that after all the pain of 2020 a lot of people are worried and in general folks have been through so much. We’ve got to understand. We’ve got to win trust for the vaccine."

The mayor also pushed back on Gov. Andrew Cuomo's threat to fine hospitals that fail to use their vaccine allotment within seven days.

"They don’t need the threat of fines," de Blasio said. "If the state of New York says, you get [a] $1 million fine if you move too quickly and [a] $100,000 fine if you move too slowly, that doesn’t get anyone anywhere."

-ABC News' Aaron Katersky contributed to this report.

Alabama, Arizona, Arkansas, California, Georgia, North Carolina, South Carolina, Texas and Virginia all reported record COVID-19 hospitalizations Monday, according to an ABC News analysis of data from The COVID Tracking Project.

When hospitalizations rise, deaths tend to follow, according to health experts. With the spread of more contagious COVID-19 variants, more people will "end up dying from this virus," Dr. Ashish Jha, dean of Brown University's School of Public Health, warned during an interview with "Good Morning America" on Tuesday.

Even with delays in reporting because of the holidays, hundreds of thousands of Americans are still testing positive each day. Monday marked two consecutive months that the U.S. has recorded more than 100,000 new cases every day.

-ABC News' Arielle Mitropoulos contributed to this report.

The head coach for the Cleveland Browns, Kevin Stefanski, has tested positive for COVID-19, the Browns announced in a Twitter statement Tuesday.

The football team's contingency plan is to have special teams coordinator Mike Priefer serve as acting head coach. The news comes just before the Browns' first NFL playoff game in 18 years on Sunday.

In addition to Stefanski, two coaching staff members and two players tested positive. The team's facility is currently closed for contact tracing purposes.

-ABC News' Michael Kreisel contributed to this report.

As hospitals across Los Angeles County reach capacity, ambulance crews have been told not to transport patients with little chance of survival.

The Los Angeles County Emergency Medical Services Agency issued the order Monday with immediate effect, saying "adult patients in blunt traumatic and nontraumatic out-of-hospital cardiac arrest" shall not be brought to the hospital if they cannot be resuscitated in the field due to the "severe impact" of the coronavirus pandemic on the health care system. That includes victims of heart attacks, gunshot wounds, stabbings and car crashes.

Los Angeles County has the highest tally of confirmed COVID-19 cases and deaths of any county in the United States, according to a real-time count kept by Johns Hopkins University.

Data posted by the Los Angeles County Department of Public Health shows there were 7,697 people who remained hospitalized with COVID-19 on Monday.

The United Kingdom saw another day of rising coronavirus cases, deaths and hospitalizations, according to the British government.

The nation recorded 54,940 new cases Sunday, bringing the total number of cases to 3,072,349, the health data showed. The seven-day average for new cases rose from 21,698 on Dec. 10 to 61,106 on Jan. 1, the British government said.

The U.K. saw 563 new COVID-19-related fatalities Sunday, according to the health data. The country has 81,431 total deaths since the start of the pandemic, the government said.

There are currently 32,294 people hospitalized in Britain. The seven-day average for new hospital admissions rose from 1,728 on Dec. 10 to 3,345 on Jan. 1, officials said.